June '22

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B U S I N E S S S T R A T E G I E S T H E D I G I T A L E Y E 8 4 G R A P H I C S P R O J U N E 2 0 2 2 G R A PH I C S - PR O.C O M the web but not for work-in-progress because JPEG does not support layers, alpha channels, or any other embedded editing features. JPEGs are also commonly used as at- tachments to emails due to their very e- cient compression scheme that produces images of smaller size that download and open quickly. GIF (Graphics Interchange Format) GIF images use a color look up table (CLUT) to distill the 16,777,216 colors of the original image into an image con- taining a maximum of 256 colors. Several graphics programs have capabilities that can create a specic palette with a pre- cise number of colors. (Fig. 6) Sometimes GIF applies the closest color in the CLUT to represent each pixel, and sometimes it uses dithering to adjust color of adjacent pix- els to better simulate blended colors. GIF compresses by dimin- ishing bit depth, and by re- placing commonly occurring patterns in large areas of solid color with an abbreviation. For example, let's say an area of 9 pixels is white; GIF will encode it as 9/255. GIFF format also supports animation. An image with a sequence of layers can be converted to GIF to pro- duce a simple animation for web publications. PNG (Portable Network Graphic) PNG format is lossless and maintains quality with limited compression. PNG nds recurring patterns in an image that it can use to compress le size. It uses a lossless two-stage compression scheme known as deate. PNG was originally created to improve upon and replace GIF as an image-le format not requiring a patent license. e PNG (pronounced "ping") acronym uno- cially stands for PNG's Not GIF. PNG supports palette-based images with palettes of 24-bit or 32-bit RGB colors and grayscale images. PNG is used as a web format or a screen capture format and not for professional-quality print graphics, as it does not support non-RGB color spaces such as CMYK. CRW (Camera Raw) and DNG (Dig- ital Negative) CRW les contain all the image data captured by a digital camera's sensor. Images can be exported to a computer and opened in the Camera Raw inter- face which oers a wide variety of non- destructive editing options. Camera Raw provides enhanced control over exposure, white balance, and several other settings. Depending on the camera from which the le was shot, the raw setting can pro- duce a second JPEG le or an XMP (Ex- tensible Metadata Platform) le that con- tains the cameras data. XMP is a labeling technology that embeds data about a le, known as metadata, into the le itself. DNG is a publicly dened and open access raw format developed by Adobe. When a Camera Raw image is saved from the Photoshop Camera Raw interface it is saved as a DNG. PSD (Photoshop Document) and PSP (Paint Shop Pro) PSD And PSP are the proprietary native format of Adobe Photoshop (PSD) and Corel PaintShop Pro (PSP), both main- stream image editing programs. ese are preferred work-in-progress formats because they retain all the editing features of the applications. PSB (Large Format Document) Sometimes referred to as Photoshop Big, Fig. 6: GIF images use a CLUT (color look up table) to distill the 16,777,216 colors of the original image into an image containing anywhere from 2 to 256 colors. Fig. 7: at trttr tnion at t n o a na a a i irn in t rt o or na otpt Fig. 7: at trttr tnion at t n o a na

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